The studies described in this grant are designed to investigate the interrelationships between the mechanisms regulating growth and sexual maturation. The specific aim is to investigate the effects of growth hormone (GH) deprivation during various stages of development of the young animal on puberty. GH deprivation will be accomplished by passively immunizing the animals with antiserum raised against growth hormone-releasing hormone (GHRH). This methodology is ideal in that it represents a non- invasive functional lesion of the neuroendocrine axis controlling GH secretion and growth which is highly specific and yet reversible. The studies represent a portion of ongoing long-term studies designed to characterize the physiological relationship between GHRH and GH as it relates to normal growth and development.